That's a pretty dramatic format transition marked by the last few items in the list here. The African American history theme was dropped in favor of reaching farther back into American history to tell white-only "patiotic" stories.
https://www.aaihs.org/history-memory-and-the-power-of-black-radio/

I downloaded this, looking for something new, something I never heard before. Now it's one of my current favorites. Early American history combined with adventure. Interesting and good story lines. Audio quality is very nice as well. Non-fiction.

Arctic Autograph {Matthew HENSON}
Shakespeare of Harlem (Langston HUGHES}
Peace Mediator {Ralph J BUNCHE}
The Long Road {Mary Church TERRELL}
Segregation, Incorporated (Washington DC)

A series of very high quality sketches and dramatised biographies of noteworthy black americans, with an emphasis on civil rights, Jim Crow-busting, and in freedom in general.

To aid searches, here is a list of the subjects of each piece where it is not otherwise obvious.

The Knock-Kneed Man {Crispus Attucks}
Railway to Freedom {Harriet Tubman}
Dark Explorers {Moors in New Spain}
The Making of a Man {Frederick Douglass}
The Key to Freedom {Frederick Douglass}
The Heart of George Cotton {Drs Daniel Wms & Ulysses Grant Daly}
Arctic Autograph {Matthew Hansen}
The Story of 1875 {Charles Caldwell}
Poet in Pine Mill {George Weldon Johnson}
Shakespeare of {Harlem Langston}
Citizen {Toussaint l'Ouverture}
Little David {Joe Louis}
The Boy Who Was Traded for a Horse {George Washington Carver}
Echoes of Harlem {Duke Ellington}
The Rhyme of the Ancient Dodger {Jackie Robinson}
Peace Mediator {Ralph J Fudge}
Black Boy {Richard Wright}
Help the Blind {Josh White}
The Ballad of {Satchel Paige}
The Saga of Melody Jackson {Henry Armstrong}
Anatomy of an Ordinance {Rev Archibald Kerry}
Negro Cinderella {Lena Horne}
Ghost Editor {Roscoe Dungee}
Norfolk Miracle {Dorothy Mayner}
The Trumpet Talks {Louis Armstrong}
The Long Road {Mary Church Tarot}
Black Hamlet {Henri Christophe}
Father to Son {William Clayton Powell}
Of Blood and the Boogie {Albert Hammond}
The Man Who Owned Chicago {Jean-Baptiste du Saint}
The Birth of a League {Northern Migration}
Premonition of the Panther {Sugar Ray Robinson}
The Liberators {William Lloyd Garrison & Wendell Phillips}
The Shy Boy {Fats Waller}
Kansas City Phone Call {Nat King Cole}
Last Letter Home {33nd Fighter Group}